I was wondering if anyone has actually made a rock structure in their tank that is hollow and actually floats. I am thinking about making something that I can grow corals on that would be suspended mid water column by being hollow, and connected to a heavy rock on the bottom by fishing line. My reasoning for this is that if I make what people call a floating reef, it is really just rock on clear columns. I worry that coraline growth on the columns would defeat the purpose over time or result in a lot of cleaning. With my proposal, the rock structure would also sway in the current giving it a really cool animation. Think of it as something that looks like those floating mountains in the movie Avatar, but they would be constantly moving though. My plan is to eventually get some blown glass that is in unique shapes, but start my proof of concept using a small bottle that will be hung upside down so I can add or remove water from it to get different buoyancy for different affects (also to reduce that size of the anchor rock). I also figure that over time as the corals grow on the float, I will need to add buoyancy to keep it from sinking, so I could just use an air line to get a couple of bubble in it as needed.
One of the reasons I am thinking about this is because my tank is so grown out that it is hard to find places to put new frags and this option will be easy to transport to other tanks, move around or trade with friends when they grow out.
Has anyone done something like this and can comment or provide pics?
Here is a picture of a candidate bottle that has been in my tank for a couple of years, I just wish I had put it in upside down so it would be easier for this project. Of course it may be easier to just start over with a different bottle or use blown glass.
